feat(routing): per-task rules on top of complexity tiers; hosted router is the default

The router has always returned two signals — task label and complexity tier —
but only the tier picked models. [routing.tasks] adds `label → ordered models`:
a matching rule's models lead the candidate chain and the tier chain follows as
fallback, so pinning translations to a local model never weakens failover.
Requests whose chain was headed by a task rule report
route_source "router+task-rule".

The Routing page grows a per-task editor built from the account's LIVE
taxonomy (GET /v1/taxonomies via the new /admin/api/routing/labels proxy;
built-in label set when the router is unreachable), with localized task names,
each task's share of 7-day traffic, "by complexity (no rule)" as the explicit
empty state, and custom labels for other taxonomies. Deleting a model scrubs
it from task rules like it always did from tiers.

Also fixes the default config pointing at a placeholder localhost:8080 router
with a nonexistent taxonomy — a fresh install now targets the hosted allaigate
router (IP endpoint, verify_tls off, data-assistant, 12 s oracle timeout) and
degrades gracefully until a key is set. Verified end-to-end against the live
router: translation → task-rule model, math → tier path.

16 new strings in all 7 languages.

config/gateway.example.toml

@@ -14,11 +14,11 @@ listen = "0.0.0.0:9000"
 # NOTE: on hard prompts the router escalates to an oracle LLM (~10 s) — for the
 # hosted router set timeout_ms = 12000+, otherwise the gateway degrades to default.
 [router]
-url         = "http://localhost:8080"
+url         = "https://138.226.222.209"   # hosted allaigate router (or your own cortiq-router URL)
 api_key_env = "CORTIQ_ROUTER_KEY"   # name of the env var holding the router key
-timeout_ms  = 800                    # timeout for the /v1/route call (12000+ for oracle)
-taxonomy_id = "general.task-type"    # for allaigate: "data-assistant"
-verify_tls  = true                   # false if the router uses an IP / self-signed cert
+timeout_ms  = 12000                  # hard prompts escalate to an oracle (~10 s)
+taxonomy_id = "data-assistant"       # the hosted router's task taxonomy
+verify_tls  = false                  # the hosted endpoint is IP-bound; true for your own domain
 
 # --- how to pick the text to classify from the conversation -----------------
 [route]